Aircraft, Engine, Propeller, and Application Equipment Inspection
Airframe and Powerplant Considerations
Agricultural aircraft are built for low-level work in demanding environments. The airframe must withstand spray corrosion, and the engine must deliver reliable power at low altitude with rapid throttle changes. Candidates should understand preflight inspection items specific to agricultural aircraft: spray system integrity, boom and nozzle condition, hopper mounts, and emergency dump functionality. The propeller is exposed to abrasives and chemical spray, so blade erosion and tracking are critical inspection points.
Spray System Components
Know the function of the pump, pressure regulator, flow control valve, boom, nozzles, and the emergency jettison system. Nozzle type and orientation determine droplet spectrum, which affects drift and coverage. A common trap is confusing pressure with flow rate: changing nozzle size changes flow, while pressure changes affect droplet size. Another trap concerns the wind-driven pump versus engine-driven pump and their failure modes.
Worked Example
If a question asks what to check when spray coverage is uneven across the swath, the rule of thumb is to verify nozzle condition and alignment first, then check boom pressure uniformity. A partially clogged nozzle reduces flow and distorts the pattern even if system pressure reads normal.
Inspection Traps
Questions often test whether a discrepancy grounds the aircraft. Any defect affecting the spray system's ability to shut off or jettison is a no-go item. Also know that maintenance must be performed by authorized personnel and recorded, and that return to service requires proper certification.